#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;

//求1+2+3+...+n
int Sum_Solution(int n)
{
    int res = n;
    n && (res += Sum_Solution(n - 1));
    return res;
}

void test()
{
    cout << Sum_Solution(100) << endl;
}

int main()
{
    test();
    return 0;
}